Joe’s Weather Blog: Bitter cold and more snow on tap (WED-2/27)
One note…I will be posting a special weather blog around 9AM on Friday…you may want to set a reminder about it on your phone so you can check it out.
The miserable winter of 2018-19 continues. Today the issue was a tiny bit of freezing mist/drizzle overnight and a cold air mass refrigerated more because of all the snow just north of the KC area. Yesterday when I was looking over the maps and taking a day off from the blog I kept thinking to myself how cold it was just north of KC…some of that dribbled into the region and now that it’s here I’d be surprised if we see a lot of change in the temperatures for the next couple of days.
Rest of today: Perhaps some later PM breaks in the clouds but cold and gray mostly with highs near 20°
Tonight: Some brief clearing and colder with lows near 10°…some areas may get colder north of KC depending on the clouds
Thursday: Variable clouds and cold with highs in the 25-30° range
Friday: Partly cloudy with highs around 40°
So some minor changes over the past couple of days but the overall trends remain…a nasty cold air mass comes into the area over the weekend…extremely cold air for early March comes with it and temperatures will be awfully cold into Wednesday of next week. No need to rehash that really since it’s been talked/blogged about for about 5-10 days or so already.
The timing of the coldest air though is now more Sunday>Wednesday or so.
Saturday will be cold again…and about 20° below average…and odds are under 32°.
The issue really is Sunday for 1) the cold and 2) the accumulating snow potential because while there may be flurries around on Saturday…Sunday is more problematic.
The thing about Sunday is IF it does snow…it’s going to be snowing into VERY cold air. VERY cold air is extremely effective in creating snow withe the right areas of saturation in the clouds…and that is a scenario that allows the limited moisture that moves through to create more than usual amounts of snow
As usual there are many complications…and the 1st is where this system that MAY create this issue is located…it’s actually north of the Hawaiian Islands…the animation below is via Rutgers University.
Look for Hawaii in the bottom center and now look north. See that large comma-shaped area of moisture…that is the system we’re starting to watch.
It will come into California on Saturday then cross into the Rockies Saturday evening and come out into the Plains on Sunday morning. It will obviously go through a ton of gyrations between where it is now and when it comes ashore then go through even more gyrations as it crosses over the mountains and breaks into different pieces. As usual a system that breaks into pieces creates complications.
We do know one thing for sure…the cold air will be present. That’s a good thing and perhaps a hindrance because IF the cold air comes in stronger we fight lots of dry air as the system, which is in pieces, fights the dry air as the snow is falling. That could be an issue. IF we get just enough cold air for better “fluff factor” snow…and that air is more easily saturated…then we get more snow. IF the cold air is overwhelming a shift farther south of the accumulating snow is possible too.
The needle in the haystack is a functional wave coming along the I-70 corridor area with enough saturated cold air to create snow. That is a scenario that remains on the table. That means 1/4″ of moisture will turn into almost 4-5″ of snow. As a matter of fact this may be the “fluffiest” snow of the year/season so far…20:1 ratios are on the table with this…maybe even greater than that.
The GFS model shows these ratios for Sunday during whatever may come through…
22:1…what does that mean…well we typically talk about 10″ of snow being equivalent to 1″ of rain…you’ve probably heard that before. So let’s start playing with that ratio…that is a 10:1 ratio. That means 5″ of snow is 1/2″ of rain…follow that? Break it down more. That means that 2.5″ of snow is 1/4″ of rain.
Now let’s have a bit of fun and extend that to let’s say 20:1 ratios. That means that instead of 10″ of snow…now that SAME 1″ of moisture is equal to 20″ of snow. See the difference. Take it farther down…1/2″ of moisture is now 10″ of snow…and 1/4″ of moisture is now 5″ of snow. Essentially we’ve doubled the snow with the SAME amount of moisture.
So let’s start there…how much moisture is the GFS model cranking out between 6PM SAT>6PM SUN…
So that’s pretty widespread 1/4″ to 1/3″+ totals…a few bulls-eyes of higher totals in there.
Now think about what would happen to those totals IF we had (and we will) those higher ratios…so you convert that moisture by a factor of 2 and then that is how much snow is possible IF ALL that moisture was snow that stuck.
Let me play devils advocate for a second…and let’s just take off 1/10″ for evaporation and saturating the atmosphere…so let’s just say we’re coming up with .2>.3″ of moisture overall…now double that for snow. You can see what the GFS is thinking about at least.
Of course the GFS has done poorly. It had a snowstorm here for Friday (won’t happen) for many runs. It had a snow storm here for Saturday…now it’s Saturday night into Sunday AM.
The EURO has been pretty rock solid with the potential for Sunday since last weekend I think.
Ummm a note…that is a LOT of moisture on the southside. Even IF you wipe off the 1st 1/10″ or so…that is a LOT of snow potential.
You can see how a shift north or south would change things dramatically.
Regardless with the “fluff factor” this is a concerning look for Sunday travel, especially in the morning.
It’s not so much because of this great functional storm coming through the flow along the I-70 corridor…this will be much more of a functional system down into Dixie…maybe severe weather again down there too into the SE part of the country especially into the Carolina’s. We just have broad lift in the atmosphere into VERY cold air that doesn’t hold moisture well. So it creates efficient snow production and that can add up.
So let’s just say we get 3-6″ of snow…the air mass coming into the area on Sunday into Tuesday is potently cold. The temperature of the air a few thousand feet up is forecast to be -19°C off the EURO model…that is the same as -2°F…that would be for Noon Sunday…in March no less. At the more traditional height…the 850 mb level…or about 5,000 feet up…it’s forecast to be -16° C or about +3° F. I thought this would be some sort of near record cold air mass…but I just looked at all the balloon reports for the month of March sent up from Topeka going back to about 1950…and this would just barely be a Top 25 cold air mass (at least at 5,000 feet up that is-for March). The coldest, at that level, is almost -23°C or almost -9° F. Interestingly this occurred in late March of 1955!
The things I learn from writing the blog. I wonder if there are similarities to the surface map on that morning 3/26/1955 and the forecast map for Sunday…hmmm.
Now the forecast map for Sunday…
Sometimes I crack myself up. Oh and back in 1955…there was 2″ of snow on the ground in late March too!
Our feature photo comes from Vicki Anderson Dolt